1. Field of the Invention
This invention relates to a seat post for a bicycle seat and more particularly to a suspension seat post for a bicycle seat having means for preventing side-to-side seat travel.
2. Description of the Related Art
Many types of suspension seat posts have been previously provided for bicycle seats in an effort to reduce the shock imparted to the rider's seat. In the past, the majority of the suspension seat posts utilized a slider which was slidably mounted in a tubular member which in turn was inserted into the bicycle frame. Usually, elastomeric damping members were positioned between the lower end of the slider and the lower end of the tubular housing with the elastomeric members being compressed by the slider as relative movement occurred between the slider and the tubular member in which it was slidably received. A seathead base is secured to the upper end of the slider to which the bicycle seat is attached. If the slider is cylindrical in design and is slidably received in a cylindrical housing, it is very difficult to prevent side-to-side seat travel. In an attempt to reduce or eliminate the side-to-side seat travel, sliders having a hexagonal or non-round cross-section have been provided which were slidably received in bushings having hexagonal or non-round bores extending therethrough with the bushings being secured or positioned in a tubular housing. Although the hexagonal and non-round sliders did reduce side-to-side seat travel considerably, the machining of the same, as well as the production of the bushings, was difficult to control with the finished product still suffering from some side-to-side seat travel. The side-to-side seat travel also increases as the bushings become worn through use.
Heretofore, the inventor herein utilized spaced-apart upper and lower bushings positioned in a tubular housing with the upper and lower bushings having hexagonal or non-round bores formed therein which receive a hexagonal or non-round slider. Applicant provided external threads on the upper bushing with those external threads being slightly exposed above the upper end of a tubular housing. A lock ring was threadably mounted on the upper end of the upper bushing and was tightened into engagement with the upper end of the tubular member to slightly turn the planes of the upper bushing into frictional engagement with the planar surfaces of the hexagonal or non-round slider to reduce side-to-side seat movement. However, careless tightening or over-tightening of the lock ring on the upper end of the upper bushing resulted in the upper bushing becoming inoperative in a fairly short time.